Impact of Land Use on Karst Water Resources—A Case Study of the Kupa (Kolpa) Transboundary River Catchment

Ana Selak,Josip Terzić,Ivana Boljat,Jasmina Lukač Reberski,Barbara Čenčur Curk

doi:10.3390/w12113226

Abstract

This paper presents a qualitative approach for assessing land-use pressures on the water resources of a transboundary Dinaric karst catchment of the Kupa River in Southeast Europe. Spatial analyses of the water quality indices for surface water and groundwater were carried out in a GIS environment, as well as a detailed assessment of man-made hazards based on recommendations of COST Action 620. The produced maps provide an insight into the qualitative status of water resources at a regional scale by indicating areas of potential negative impacts of land use through the identification of point and diffuse sources of pollution. Higher values of the water quality indices for surface water and groundwater are observed in lowland areas, karst plateaus and poljes, where the impacts of anthropogenic activities such as agriculture and quarries take place on karstified permeable carbonate rocks. Hazard assessment showed how transport infrastructure induces a low hazard level. Settlement areas without proper sewerage systems impose moderate hazard levels, while direct wastewater discharges into groundwater and waste illegally disposed in karst swallow holes and caves located near settlements were classified as having high hazard levels. The applied methods proved to be suitable even in challenging karst environments where the complex properties and structure make the exploration and monitoring of groundwater resources difficult and scarce.

Highlights

Frequent weather extremes coupled with unsustainable land-use practices and exacerbated by spatially heterogeneous water resources allocation due to complex hydrogeological conditions, pose various challenges in terms of water quantity and quality
This was followed by an assessment of the man-induced hazards according to the Water quality index (WQI) mapping based on the methodology proposed in the CC-WARE project [12] and a detailed hazard assessment and mapping based on the methodology proposed in COST
Normalized water quality index for surface waters (WQIsw) values were applied to Corine Land Cover (CLC) categories, which were identified within the

Summary

Introduction

Frequent weather extremes coupled with unsustainable land-use practices and exacerbated by spatially heterogeneous water resources allocation due to complex hydrogeological conditions, pose various challenges in terms of water quantity and quality. Driven by various socio-economic factors and affected by climate change, land-use changes have a negative impact on water resources, especially on vulnerable karst groundwater sources used for water supply [1,2]. Sustainable development that implies a synergy between economic and spatial growth, water resource management and protection objectives, while adapting to climate change, is of strategic importance for transboundary catchments like the Kupa (in Slovenian Kolpa) River basin [3]. To adequately manage and protect this part of the Danube River basin, decision-makers need to address ongoing water protection and flood risk issues at the local and national levels and at the transnational level. Water 2020, 12, 3226 management routines for the impacts of land use on the water regime in the Danube River basin.

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Conclusion